[gcc r16-6017] vect-generic: Fix expand_vector_mult [PR123069]

[Jakub Jelinek]

https://gcc.gnu.org/g:9029f5436aa4badd17c63a5633346a620d265ef5

commit r16-6017-g9029f5436aa4badd17c63a5633346a620d265ef5
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Dec 10 18:07:02 2025 +0100

    vect-generic: Fix expand_vector_mult [PR123069]
    
    The r16-5095 PR122065 change added build_int_cst call on vector types.
    That is never correct, it ICEs already on the TYPE_PRECISION used at the
    start of wide_int_to_tree_1.
    
    Fixed by using build_zero_cst instead.
    
    2025-12-10  Jakub Jelinek  <jakub@redhat.com>
                Andrew Pinski  <andrew.pinski@oss.qualcomm.com>
    
            PR middle-end/123069
            * tree-vect-generic.cc (expand_vector_mult): Use
            build_zero_cst (vectype) instead of build_int_cst (vectype, 0).
    
            * gcc.c-torture/compile/pr123069.c: New test.

Diff:
---
 gcc/testsuite/gcc.c-torture/compile/pr123069.c | 9 +++++++++
 gcc/tree-vect-generic.cc                       | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.c-torture/compile/pr123069.c b/gcc/testsuite/gcc.c-torture/compile/pr123069.c
new file mode 100644
index 000000000000..756e243d992f
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr123069.c
@@ -0,0 +1,9 @@
+/* PR middle-end/123069 */
+
+__attribute__((__vector_size__ (2 * sizeof (long long)))) unsigned long long v;
+
+void
+foo (void)
+{
+  v *= 0xffffffff00000000ULL;
+}
diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
index e980a66e8809..dc4cb1ba8f4b 100644
--- a/gcc/tree-vect-generic.cc
+++ b/gcc/tree-vect-generic.cc
@@ -627,7 +627,7 @@ expand_vector_mult (gimple_stmt_iterator *gsi, tree type, tree op0,
 	}
       tree accumulator, tmp_var;
       if (alg.op[0] == alg_zero)
-	accumulator = build_int_cst (vectype, 0);
+	accumulator = build_zero_cst (vectype);
       else
 	accumulator = op0;